Pathogenesis (development of disease)
Blepharitis can result from a variety of triggers:
- Infections:
- Viruses: herpes simplex, herpes zoster
- Bacteria: Staphylococci and Streptococci; Pseudomonas, Proteus and anaerobes.
- Parasites: Pediculosis pubis (crab lice infestation), Pediculosis capitis (head lice infestation).
- Mites: Dermatophagoides pteronyssinus and Dermatophagoides farinae.
- Skin diseases (see below).
- External factors: see below “Behavioral causes” and “Environmental pollution – intoxications (poisonings)”.
Etiology (causes)
Behavioral causes
- Exposure to dry dusty air; smoke.
- Frequent eye rubbing
- Chemical substances (e.g. in cosmetics).
- Insufficient hygiene
Disease-related causes
Eyes and eye appendages (H00-H59).
- Allergic blepharitis – mainly triggered by eye ointments or cosmetics.
- Rosacea (copper rose) – chronic inflammatory, non-contagious skin disease that manifests on the face; papules (nodules) and pustules (pustules) and telangiectasias (dilatation of small, superficial skin vessels) are typical
- Refractive anomalies – deviations from the refractive ratios such as myopia / hyperopia.
Skin and subcutaneous (L00-L99)
- Atopic eczema (neurodermatitis)
- Seborrhea (oily skin)
- Scaling skin inflammation, unspecified
Infectious and parasitic diseases (A00-B99).
- Infectious blepharitis – mainly caused by viruses (herpes simplex, herpes zoster); bacteria (staphylococci and streptococci; Pseudomonas, Proteus, and anaerobes); parasites (pediculosis pubis (crab lice infestation), pediculosis capitis (head lice infestation)); mites (Dermatophagoides pteronyssinus and Dermatophagoides farinae/dust mite allergy).
Environmental pollution – intoxications (poisonings).
- Smoke
- Dust
- Temperature extremes: heat and cold
- Draft/wind
Further
- Dysfunction of the sebaceous glands (meibomian glands) at the edge of the eyelid, so that too little or too much sebum is produced.